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    <title>graypolarplot</title>
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    <center>Scilab Function</center>
    <div align="right">Last update : 16/12/2004</div>
    <p>
      <b>graypolarplot</b> - Polar 2D plot of a surface using
  colors</p>
    <h3>
      <font color="blue">Calling Sequence</font>
    </h3>
    <dl>
      <dd>
        <tt>graypolarplot(theta,rho,z,[strf,rect])</tt>
      </dd>
    </dl>
    <h3>
      <font color="blue">Parameters</font>
    </h3>
    <ul>
      <li>
        <tt>
          <b>rho</b>
        </tt>: a vector with size n1, the discretization of the radius</li>
      <li>
        <tt>
          <b>theta</b>
        </tt>: a vector with size n2, the discretization of the the
          angle.</li>
      <li>
        <tt>
          <b>z</b>
        </tt>: real matrix of size (n1,n2). <tt>
          <b>z(i,j)</b>
        </tt> is the value
          of the surface at the point (rho(i),theta(j)).</li>
      <li>
        <tt>
          <b>strf</b>
        </tt>: is a string of length 3 <tt>
          <b>"xy0"</b>
        </tt>.<ul>
          <li>
            <tt>
              <b>default</b>
            </tt>The default is <tt>
              <b>"030"</b>
            </tt>.</li>
          <li>
            <tt>
              <b>x</b>
            </tt>: controls the display of captions.<ul>
              <li>
                <tt>
                  <b>x=0</b>
                </tt>: no captions.</li>
              <li>
                <tt>
                  <b>x=1</b>
                </tt>: captions are displayed. They are given by the
                      optional argument <tt>
                  <b>leg</b>
                </tt>.</li>
            </ul>
          </li>
          <li>
            <tt>
              <b>y</b>
            </tt>: controls the computation of the frame.<ul>
              <li>
                <tt>
                  <b>y=0</b>
                </tt>: the current boundaries (set by a previous call to
                      another high level plotting function) are used. Useful
                      when superposing multiple plots.</li>
              <li>
                <tt>
                  <b>y=1</b>
                </tt>: the optional argument <tt>
                  <b>rect</b>
                </tt> is used to
                      specify the boundaries of the plot.</li>
              <li>
                <tt>
                  <b>y=2</b>
                </tt>: the boundaries of the plot are computed using min
                      and max values of <tt>
                  <b>x</b>
                </tt> and
                      <tt>
                  <b>y</b>
                </tt>.</li>
              <li>
                <tt>
                  <b>y=3</b>
                </tt>: like <tt>
                  <b>y=1</b>
                </tt> but produces isoview
                      scaling.</li>
              <li>
                <tt>
                  <b>y=4</b>
                </tt>: like <tt>
                  <b>y=2</b>
                </tt> but produces isoview
                      scaling.</li>
              <li>
                <tt>
                  <b>y=5</b>
                </tt>: like <tt>
                  <b>y=1</b>
                </tt> but <tt>
                  <b>plot2d</b>
                </tt> can
                      change the boundaries of the plot and the ticks of the
                      axes to produce pretty graduations. When the zoom button
                      is activated, this mode is used.</li>
              <li>
                <tt>
                  <b>y=6</b>
                </tt>: like <tt>
                  <b>y=2</b>
                </tt> but <tt>
                  <b>plot2d</b>
                </tt> can
                      change the boundaries of the plot and the ticks of the
                      axes to produce pretty graduations. When the zoom button
                      is activated, this mode is used.</li>
              <li>
                <tt>
                  <b>y=7</b>
                </tt>: like <tt>
                  <b>y=5</b>
                </tt> but the scale of the new
                      plot is merged with the current scale.</li>
              <li>
                <tt>
                  <b>y=8</b>
                </tt>: like <tt>
                  <b>y=6</b>
                </tt> but the scale of the new
                      plot is merged with the current scale.</li>
            </ul>
          </li>
        </ul>
      </li>
      <li>
        <tt>
          <b>leg</b>
        </tt>: a string. It is used when the first character x of argument
          <tt>
          <b>strf</b>
        </tt> is 1. <tt>
          <b>leg</b>
        </tt> has the form
          <tt>
          <b>"leg1@leg2@...."</b>
        </tt> where <tt>
          <b>leg1</b>
        </tt>,
          <tt>
          <b>leg2</b>
        </tt>, etc. are respectively the captions of the first
          curve, of the second curve, etc. The default is <tt>
          <b>""</b>
        </tt>.</li>
      <li>
        <tt>
          <b>rect</b>
        </tt>: This argument is used when the second character y of argument
          <tt>
          <b>strf</b>
        </tt> is 1, 3 or 5. It is a row vector of size 4 and
          gives the dimension of the frame:
          <tt>
          <b>rect=[xmin,ymin,xmax,ymax]</b>
        </tt>.</li>
    </ul>
    <h3>
      <font color="blue">Description</font>
    </h3>
    <p>Takes a 2D plot of the surface given by <tt>
        <b>z</b>
      </tt> on a polar
    coordinate grid defined by <tt>
        <b>rho</b>
      </tt> and <tt>
        <b>theta</b>
      </tt>. Each
    grid region if filled with a gray or color level depending on the average
    value of <tt>
        <b>z</b>
      </tt> on the corners of the grid.</p>
    <h3>
      <font color="blue">Examples</font>
    </h3>
    <pre>


  rho=1:0.1:4;theta=(0:0.02:1)*2*%pi;
  z=30+round(theta'*(1+rho^2));
  f=gcf();
  f.color_map= hotcolormap(128);
  clf();graypolarplot(theta,rho,z)
 
  </pre>
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